make packers a top-level export

ts/export/index.ts

@@ -1,2 +1,3 @@
 export { LocalPacker } from "./packer/local";
 export { ExpressPacker } from "./packer/express";
+export { Packer } from "./packer/packer";

ts/index.ts

@@ -2,3 +2,4 @@ export * from "./docx";
 export * from "./export";
 export { Numbering } from "./numbering";
 export { Styles } from "./styles";
+export * from './export';